The goal of this project is understanding how a cell coordinates the expression of its genetic repertoire as a function of growth rate and nutritional sufficiency. Previous annual reports have concerned genetic and physiological characterization of guanosine 3',5'-bispyrophosphate (ppGpp) which has emerged as a major signal regulating these processes and the three regulatory mechanisms affecting the intracellular concentration of ppGpp. Regulation of ribosimal RNA cistron expression has long been the paradigm of coordinate gene-expression but the mechanism by which this occurs has been elusive. This year we report finding a means of measuring the in vivo regulatory effects of ppGpp on rRNA cistron expression directly on RNA transcripts using plasmids bearing fusions of ribosomal tandem promoter and terminator regions. The upstream promoter is sensitive to ppGpp whereas the downstream promoter is unexpectedly insensitive to ppGpp but nevertheless sensitive to growth rate by an unknown mechanism. Transcription elongation and termination are unaffected by ppGpp. The metabolic stability of transcripts is unexpectedly prolonged by inhibition of protein synthesis independent of ppGpp. We have preliminary indications of ribosomal RNA promoter specific antiterminator activity allowing read through of normally efficient terminators.